It has long been known that a sliding cover assembly for converting the open body of a pickup truck to a closed body is advantageous. The sliding cover, when closed, provides protection of the contents of the truck from bad weather and from unintended access. In addition, a closed truck bed reduces fuel consumption by reducing wind resistance. Moreover, the provision of a cover over the truck bed reduces the risk of cargo being lost due to strong airflows across the truck bed while the truck is moving. With the cover retracted such that the body is open, the truck is available to be used to transport large and bulky objects that would not be transportable in the closed body of the truck.
A sliding cover assembly mounted on a pair of tracks fixed to the upper side walls of a truck body is known, as shown in U.S. Pat. No. 4,611,848 to Romano. Such prior art cover assembly includes side wall tracks having lengthwise channels communicating with the interior space of the open body, with a retractable cover being slidably mounted in the tracks. The cover is translated forward to uncover the body and rearward to cover the body. The cover is stowed in the forward portion of the body by winding the cover upon a spring-loaded drum. As the cover is pulled rearwardly, the spring resists movement such that upon release from the extended position, the spring pulls the cover back into the retracted position. This mechanical, spring-operated system is unwieldly in use, expensive and difficult to manufacture.
U.S. Pat. No. 4,210,361 to Marvin et al also discloses a cover assembly which rolls up on a drum pursuant to spring tension. The Marvin et al cover also includes a latch on the end of the cover having outwardly extending plungers to engage tangs specially formed on the truck tailgate and matching holes in the guiderails. This locking mechanism is mechanically complicated and requires modifications to the vehicle.
Thus it can be seen that there is no simple and economically manufactured sliding pickup bed cover currently available. The ideal cover would be free from complex mechanical storage mechanisms, and enable automatic locking of the cover and the tailgate upon full extension of the cover.